I was there when my grandmother died. I was urged to say something as she went but couldn't as I had already said everything I needed to say during our front porch conversations where she would tell me that kids shouldn't have to be sad like we were and answered my questions about life.
The idea of sending people off with peaceful words doesn't make sense to me. The peaceful words, the staggering revelations, the infinite bounty of love should be said during life, not on the brink of life everlasting.
Whispering wonders to the dead and dying is about as useful as painting a broken window. It looks pretty, but what does it really do?